diff --git a/.github/workflows/pr-unit-tests.yml b/.github/workflows/pr-unit-tests.yml
index d377efc00..2f73a3dd3 100644
--- a/.github/workflows/pr-unit-tests.yml
+++ b/.github/workflows/pr-unit-tests.yml
@@ -10,22 +10,13 @@ jobs:
       fail-fast: false
       matrix:
         # We test against the earliest and latest PHP versions for each major supported version.
-        php: [ '5.6', '7.0', '7.4', '8.0' ]
-        wp: [ '5.2', '5.3', '5.4', '5.5', '5.6', 'latest' ]
+        php: [ '5.6', '7.0', '7.4', '8.0', '8.1', '8.2' ]
+        wp: [ '6.1', '6.2', '6.3', 'latest' ]
         multisite: [ '0', '1' ]
         exclude:
-          # Earlier versions of WordPress do not support PHP 7.4+
-          - php: 7.4
-            wp: 5.2
-          - php: 8.0
-            wp: 5.2
-          - php: 8.0
-            wp: 5.3
-          - php: 8.0
-            wp: 5.4
-          - php: 8.0
-            wp: 5.5
           # WordPress 6.3+ requires PHP 7.0+
+          - php: 5.6
+            wp: 6.3
           - php: 5.6
             wp: latest
     services:
diff --git a/tests/phpunit/procedural_api/procedural_api_Test.php b/tests/phpunit/procedural_api/procedural_api_Test.php
index c8ac7314a..babe58ce5 100644
--- a/tests/phpunit/procedural_api/procedural_api_Test.php
+++ b/tests/phpunit/procedural_api/procedural_api_Test.php
@@ -227,7 +227,7 @@ public function test_unschedule_all( $time, $hook, $args, $group ) {
 
 	public function test_as_get_datetime_object_default() {
 
-		$utc_now = new ActionScheduler_DateTime( null, new DateTimeZone( 'UTC' ) );
+		$utc_now = new ActionScheduler_DateTime( 'now', new DateTimeZone( 'UTC' ) );
 		$as_now  = as_get_datetime_object();
 
 		// Don't want to use 'U' as timestamps will always be in UTC.
@@ -268,7 +268,7 @@ public function test_as_get_datetime_object_timezone() {
 		// phpcs:ignore
 		date_default_timezone_set( $timezone_au );
 
-		$au_now = new ActionScheduler_DateTime( null );
+		$au_now = new ActionScheduler_DateTime( 'now' );
 		$as_now = as_get_datetime_object();
 
 		// Make sure they're for the same time.
@@ -277,7 +277,7 @@ public function test_as_get_datetime_object_timezone() {
 		// But not in the same timezone, as $as_now should be using UTC.
 		$this->assertNotEquals( $au_now->format( 'Y-m-d H:i:s' ), $as_now->format( 'Y-m-d H:i:s' ) );
 
-		$au_now    = new ActionScheduler_DateTime( null );
+		$au_now    = new ActionScheduler_DateTime( 'now' );
 		$as_au_now = as_get_datetime_object();
 
 		$this->assertEquals( $au_now->getTimestamp(), $as_now->getTimestamp(), '', 2 );